Emergency downgraded at Wanapum Dam




Posted on March 5, 2014 at 3:09 PM

Updated Wednesday, Mar 5 at 9:30 PM

GRANT COUNTY, Wash--Engineers began focusing on repairs  Wednesday at Wanapum Dam where divers discovered a cracked pier one of the spillways a week prior.   

The crack in a spillway pier at the Wanapum Dam has been downgraded to a "non-failure emergency." The Grant County Public Utility District lowered the classification Tuesday night.

The downgrade is the result of engineering surveys conducted Monday and Tuesday that show continued stabilization of the 65-foot long crack found last week on one of the dam's spillways. As of 6:00 p.m. Tuesday, surveys show that the impacted area is stable.
The PUD says the fracture has closed and the damaged section of the spillway monolith has moved back upstream by nearly 1.75 inches. That's the result of the utility's actions to lower water above Wanapum Dam and reduce pressure on the damaged spillway.

WATCH: Emergency downgraded at Wanapum Dam

Divers used a small submarine to examine the leak, which was underwater.

Grant County Utility officials said the crack was on one of the 12 spillways that is not used for energy to pass through, but it  did cause the structure to lean a couple inches. One official said it was the most extensive structural damage the Grant County Utility District had seen.

Investigators said people living downstream should not be worried and that if the pier were to break, flooding would not be an issue.

“There wouldn’t be any flooding to downstream communities.” said Garrett Grubbs “A lot of what would be moving through there would be what we would normally see this time of year.”

After the crack was discovered, officials lowered the water 20 ft in the reservoir behind the dam dropping the water level to 545 ft above see level, the lowest it had been since 1963 when the dam was built.

Grant County Utility officials said that eased some of the pressure.

“In doing so, we stabilized that section of the dam and that makes it safer for inspectors and divers to get in there and really examine the full extent of the structural damage,” said Thomas Stredwick.

WATCH: Drawdown eases pressure on Wanapum Dam crack

The lowered water levels allowed people walking by, such as Mario Milkovic, to explore parts of the Columbia River that they normally would not be able to see.

 “They’re using metal detectors to try and see if anybody lost anything, see if we can find some treasures,” Milkovic said.

Milkovic and another man, Garrett Grubbs, both enjoyed exploring the ecosystems as well.

Investigators said it was unclear what caused the damage, but the dam would continue to provide energy to customers throughout the investigation.